Flame retardant – Definition



In Germany, the legislator prescribes the fulfilment of the Fire behaviours of building materials in §19 of the Model Building Code, the Accommodation Code and the country-specific Assembly Place Regulations. This means that these regulations apply in all areas frequented by the public. Similar regulations now exist in many countries around the world.

However, many people often only think about building regulations, i.e. building materials or escape routes, etc.


ATTENTION: Decoration materials must also be at least flame-retardant in accordance with DIN 4102 or
DIN EN 13501-1
, which is the common requirement in Germany in the technical guidelines for exhibitors, organisers, service companies, stand construction companies and service providers. At present, there is still a free choice between the German and European standards.


National fire protection standards will be replaced by a uniform DIN EN standard. Photo: Gert Altmann


DIN EN 13501-1, the European standard, is to replace the German standard in the future. The European classification for the fire behaviour of building materials describes

Decorative materials also include wall coverings, room dividers, curtains, displays, textile sails, banners, flags and the like. Not to be forgotten, however, are furniture, upholstery fabrics and the like in public authorities or schools or in public transport of all kinds.


The technical term “flame-retardant” describes in Germany the building material class B1 according to DIN 4102-1 of basically flammable products, which, however, are self-extinguishing – i.e. do not continue to burn automatically. The DIN 4102-1 standard classifies building materials and components on the basis of their fire behaviour and prescribes proof for all materials, including textiles or paper, which are not listed in Part 4 of the standard.


In order to meet the B1 criteria, the tested substances must still have an average residual length of more than 15 cm after the so-called fire shaft test and must fall below the average flue gas temperature of 200 degrees Celsius. (Video fire shaft test) Accredited testing institutes test and classify the products in accordance with the applicable standard.


Fire shaft. Photo: Material Testing Institute University of Stuttgart


According to this standard, flame-retardant building materials must meet at least class C s3 d2. A maximum of B-s1 d0 is possible in this class, the material must neither fall off burning nor emit smoke.

An additional qualification is the so-called Radiant Panel Test. The samples are heated by a radiant heater and repeatedly ignited with a small burner at the edges. The flame propagation and duration as well as dripping sample parts influence the test result.


In France, Luxembourg and Belgium the Brûleur Électrique test is carried out in accordance with standard NFP 92503 M1. The test result M1 is more important than the German B1 certification. It means non-flammable, M2 means flame-retardant.     


The test arrangement corresponds approximately to the European test, the material is arranged at an angle of 30 degrees to the radiator and ignited by means of a gas flame. The difference is that the flame is held to the fabric surface and not to the edges. The material must not burn for more than five seconds, nothing must fall off and the original size must be retained. Then it achieves the coveted M1 result, which is highly regarded throughout the world.

The test arrangements of the different countries are different in this terms:

  • the arrangement of the samples to the ignition source
  • the type of ignition source and the intensity and duration of flame exposure
  • the type of flame treatment (edge and surface flame treatment)

Here you will find detailed information on Comparison of fire protection standards and test methods.


Flame retardant materials – what are the possibilities?  

König Konzept: Schwer entflammbare Papiere, Papiersuchdienst, Produktion